The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 2005
Filed:
Mar. 15, 2002
Takao Kuwabara, Hitachi, JP;
Takao Kuwabara, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a pump turbine which can be operated in a pumping mode or a generating mode by switching the rotating direction of a runner, the discharge passing through the runner is adjusted based on a wicket gate opening; the speed of the runner is sensed; a target speed is temporarily set to a first speed different from a rated speed on generation starting; a response speed of a speed control via discharge adjusting means is controlled to a lower level after the speed reaches the target speed than that before the speed reaches the target speed; and finally, the target speed is slowly led to the rated speed, thus enhancing the stability of the speed when the turbine is started and enlarging a head range in which synchronization is achieved.